Does registering my trade name with the Department mean that I own that trade name?

First and foremost, please keep in mind that registration of a trade name with the Department DOES NOT grant you ownership of the trade name. This is probably the single greatest source of confusion, and you can avoid problems later if you understand this at the beginning.

Ownership of a trade name is acquired by using the name openly and continuously in the marketplace. Many trade names in Hawaii are not registered with the State. Nonetheless, by using those names in commerce, common law ownership rights, are acquired.